Former President Clinton lends Obama the validation of the Democratic Party's most popular elder statesman.

Receive the latest politics updates in your inbox

Former President Bill Clinton speaks at the Democratic National Convention in Denver in this 2008 file photo. The way Democrats and Republicans treat their ex-presidents at convention time reflects each man's personal popularity and also how well he's weathered changes in party politics.

President Barack Obama swept into his convention city Wednesday, eager to accept his party's nomination and make the case for re-election despite a sputtering economy.

He hoped to claim a little luster from Bill Clinton's prime-time address to the Democratic National Convention on Wednesday.

In a last-minute shift, the president ditched plans to deliver his acceptance speech before a throng of 74,000 at an outdoor stadium on Thursday, the convention's final night, citing iffy weather. With a chance of thunderstorms on the horizon, Obama will accept his party's nomination indoors before about 15,000 people at the Time Warner Cable Arena.

Memorable Moments From Democratic Conventions

Clinton's convention speech on Wednesday will be a high point in a checkered relationship between two men who sparred, sometimes sharply, in the 2008 primaries, when the ex-president was supporting wife Hillary's campaign for the nomination.

Democrats hope that as the last president to preside over sustained economic growth, Clinton can help propel this president to re-election in less rosy times. His wife — seen as a potential presidential candidate again for 2016 — will be worlds away from the debate, in distance and substance. Obama's secretary of state, midway through an 11-day tour of the Asia-Pacific region, should be in East Timor by the time her husband speaks.

Republican Mitt Romney, preparing for the fall debates at a private home in Vermont, had no public schedule on the day Obama accepts his nomination, but taped several TV interviews in nearby New Hampshire.

He framed the economic debate against Obama in an email to supporters, writing that "no president in modern history has ever asked to be re-elected with this many Americans out of work. Twenty-three million Americans are struggling for work, and more families wake up in poverty than ever before."

Obama, Biden & Faces of the DNC

GOP running mate Paul Ryan, campaigning in Iowa, kept up his running criticism of the Democrats. He predicted Clinton and the Democrats would offer "a great rendition of how good things were in the 1990s. But we're not going to hear much about how things have been in the last four years."

Ryan cast the country's economic struggles in grim terms, noting the national debt reached $16 trillion on Tuesday. "That's a country in decline," he said.

To bolster Romney and Ryan, conservative groups announced nearly $13 million in new ad spending to counter Obama's convention.

American Crossroads planned to spend $6.6 million over the next 10 days on an ad that criticizes the economy under Obama's watch and Americans for Prosperity is spending another $6.2 million on ads criticizing the Democrats' health-care overhaul.

Rahm Emanuel, the Chicago mayor who served under both Clinton and Obama, made the rounds of morning talk shows Wednesday to trace a connection between the two presidents, speaking of "similar values, similar policies and similar objectives."

Clinton "can do nothing but help" Obama, Emanuel said, rejecting any notion that Clinton's ability to get things done and work with Republicans would somehow diminish perceptions of Obama.

But former Republican New Hampshire Gov. John Sununu, writing in the New Hampshire Union Leader, said Clinton's speech "will serve to remind the world of a time when the leadership of the Democratic Party took fiscal responsibility seriously. It might even induce nostalgia for the days of balanced budgets and bipartisan accomplishments such as welfare reform."

The GOP released a new Web video showcasing the story of a man who lost his job and got back on his feet through the welfare-to-work requirements enacted under Clinton. Republican Party Chairman Reince Priebus repeated the widely debunked claim that Obama was gutting the work requirements, "holding back the prosperity of so many who are scraping to get by."

Obama adviser Valerie Jarrett, making the case for Obama's economic policies in an appearance on MSNBC, said the president has a strong argument to make that people are doing better, but she acknowledged that "Americans are sitting around the breakfast table trying to figure out to make ends meet, so we have work to do."

Maryland Gov. Martin O'Malley, chairman of the Democratic Governors Association, spoke at a breakfast with Iowa delegates and urged party activists to get fully behind Obama in the next two months.

"We have 60 days to turn to our neighbors, to find common ground, to appeal to their good intentions and to create a country of more by re-electing Barack Obama president of the United States," he said.

If Day 2 of the Democrats' convention was all about grabbing some of Clinton's star power, opening day was designed to portray Obama as someone who understands the problems of ordinary people.

Michelle Obama played those cards with force in a speech declaring that after four years as president, her husband is still the man who drove a rust-bucket on early dates, rescued a coffee table from the trash and knows the struggles of everyday Americans because he lived them in full.

"I have seen firsthand that being president doesn't change who you are. No, it reveals who you are," the first lady said to lusty cheers Tuesday night in a deeply personal, yet unmistakably political testimonial.

Mrs. Obama didn't mention Romney in her remarks. But there was no mistaking the contrast she was drawing when she laid out certain values, "that how hard you work matters more than how much you make, that helping others means more than just getting ahead yourself."

Polling gives Obama a consistent advantage over Romney as the more empathetic and in-touch leader. But the sputtering economy is the topmost voter concern and Obama's highest mountain to climb after more than 42 months of unemployment surpassing 8 percent, the longest such stretch since the end of World War II. No president since the Great Depression has been re-elected with joblessness so high.